First Lady Michelle Obama visits Sesame Street to talk with her pal Elmo about eating right, exercising regularly and being a healthy and positive role model for children. Credit: Richard Termine/©2009 Sesame Workshop. All Rights Reserved.

While maintaining an emphasis on the importance of literacy and numeracy, the 40th-anniversary season kicks off “My World is Green & Growing,” a two-year science initiative designed to increase positive attitudes towards nature, deepen children’s knowledge about the natural world and encourage behavior that shows respect and care for the environment. First Lady Michelle Obama appears in the season premiere, today at 9 a.m., and teaches “the street’s” residents about the many benefits of planting a garden and healthy eating as part of Sesame Street’s ongoing “Healthy Habits for Life” initiative.

Preview First Lady Michelle Obama’s visit to Sesame Street:

Original songs, storylines and animations will continue to stimulate the preschool viewers’ awareness and excitement about the environment. Through a series of 26 celebrity segments, Sesame Street will introduce words like “habitat,” “metamorphosis,” “hibernate,” and more to enhance children’s vocabulary and appreciation of nature. You’re sure to laugh along with the kids when you see guest spots from Hugh Jackman, Cameron Diaz, Sarah Jessica Parker, Ricky Gervais, Adam Sandler, Ziggy Marley, Tiki Barber, Kobe Bryant, and others.

Check out some of these exciting guest appearances and other highlights from Sesame Street’s 40th anniversary season:

Watch classic Sesame Street clips on WLIW21’s new video portal.

Watch Sesame Street videos, play games and more on pbskids.org.

Visit 21 Kids for WLIW21’s children’s programming schedule, video, games, and more.